With the technological advancement of communication devices, there are requirements for the services providing and sharing information the user wants. Recently, a smartphone and a tablet Personal Computer (PC) make it possible for the user to acquire and share various information through a wireless communication system.
However, in order for the user to acquire and share the information through a wireless communication system, there is a need for a communication infrastructure. In addition, the wireless communication system is not efficient to exchange trivial but useful information due to the system complexity and time delay.
Thus, a Device to Device (D2D) service has been introduced to make it possible for the devices to share device information to establish the communication link for a direct communication without a legacy communication infrastructure.
In the D2D environment, resource allocation is performed through a distributed scheduling which enables communication through a plurality of links tolerating interference on the same resource.
In order to implement the distributed scheduling without the assistance of a communication infrastructure or a controller, the device uses a Connection ID (CID) for each link. In the D2D service, the peer terminals generate a CID for the communication link in a pairing phase, the CID being limited in number, and join the scheduling in the actual traffic duration.
More specifically, in order to increase the resource reuse factor in consideration of the interference situation, an orthogonal CID-based scheduling is used. Here, the orthogonal CID denotes the CID which is not shared among adjacent links, and each terminal broadcasts the CID in use in the pairing phase to prevent the same CID from being used by other adjacent terminals.
In a case of using the orthogonal CIDs that are limited in number, however, it is difficult to support a plurality of links and, if the orthogonal CID utilization rate is low after pairing, this causes resource utilization inefficiency. Therefore, there is a need for a non-orthogonal CID.
In a case of using the non-orthogonal CID, however, the same CID may be used redundantly, resulting in an increase of collision probability.
Therefore, a need exists for a non-orthogonal CID-based scheduling method and apparatus that is capable of improving scheduling efficiency in a D2D communication system.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.